1. Field of the Invention
The present invention relates generally to fiber optic testers and more particularly to fiber optic testers that may be used in the field.
2. Background Art
Fiber optic cables are used in many systems for transmission of broad bandwidth digital and analogue signals, and are currently in prolific use in networks of all kinds, such as the internet, wide area networks, local area networks, cable, communications, and telecommunications systems. Fiber optic cables have become the transmission medium of choice for these systems.
Construction, testing, installation, and maintenance of fiber optic systems requires equipment that may be used in the field to test the fiber optic cables in a variety of installations and different circumstances. Although certain fiber optic testers have been available, such testers often do not allow for testing a plurality or multiplicity of fiber optic cables, terminations, and devices in the field, simultaneously. Fiber optic testers that have been known are either capable of only testing a single connectorized termination, strand, or cable, are complicated or difficult to use in a field environment, or are permanently installed in large installations for automated testing. As such, it has been difficult to use these fiber optic testers in the field.
Fiber optic test equipment should be quick, versatile, easy and simple to use, easily adaptable for use with different systems and configurations, inexpensive, long lasting, durable, and capable of testing a plurality of fiber optic cables and/or devices simultaneously. Such equipment should be capable of being used for continuity testing and determining whether or not there are breaks in the fiber optic cables being tested, and facilitate speeding up the construction, installation, and maintenance of the fiber optic systems. The fiber optic tester should be a portable handheld fiber optic tester capable of being used in the field.
There is, thus, a need for a fiber optic tester that may be used by a field technician for testing a variety and plurality or multiplicity of connectorized fiber optic cables and/or devices simultaneously. The fiber optic tester should be quick, versatile, easy and simple to use, easily and quickly adaptable for use with different systems and configurations, inexpensive, long lasting, light weight, safe to use, attractive, sturdy, and durable, and capable of being used in the field for testing the fiber optic cables in a variety of installations and different circumstances. The fiber optic tester should be capable of being used as a continuity tester and determining whether or not there are breaks in the fiber optic cables being tested. The fiber optic tester should be a portable handheld fiber optic tester capable of being used in the field
Different fiber optic testers have heretofore been known. However, none of the fiber optic testers adequately satisfies these aforementioned needs.
U.S. Pat. No. 6,373,562 (Marsh, et al.) discloses a fiber optic cable tester, which includes a body having an inlet fitting, an outlet and a channel that extends between the inlet fitting and the outlet. A magnification and focusing assembly is mounted within the channel between the inlet fitting and the outlet. A fiber optic cable end fitting is communicably interengaged with the inlet fitting, and light is transmitted through the magnification and focusing assembly and the channel to the outlet. The light is projected from the outlet and against a target area to produce an image, which is indicative of the condition of the fiber optic cable.
U.S. Pat. No. 5,196,899 (Serwatka) discloses a fiber optic test light with multiple connector adapters that may be used for visual continuity testing of fiber optic cables, patch cords, and pigtails, which comprises a light source, an adaptive interface, a power source, and a housing. The adaptive interface comprises a wheel having a variety of fiber optic connectorized end fittings, which may be used to match or connect various fiber optic connectorized endings and also bare fiber to a light source, thus, permitting visual testing for the continuity and integrity of a fiber optic link.
U.S. Pat. No. 6,094,261 (Contarino, Jr.) discloses a method and apparatus for distinguishing various fiber-optic cables from each other in an installation where cables are grouped together, the apparatus comprising a light source for generating a high-intensity, reasonably highly collated, colored, and pulsed light beam. The light is coupled into one end of a fiber-optic cable, whereby an installer can easily observe the corresponding light coming out of the opposite end of the cable to distinguish that cable from the other cables.
U.S. Pat. No. 5,960,130 (Pimpinella) discloses a method of testing splice connections in an optical fiber cable, in which the quality of a splice at a remote location made between an optical cable and a subsequent optical cable includes connecting a first optical switch to the optical fibers contained within the cable. The first optical switch is connected to the optical fibers at a central office from where the optical cable originates. The first optical switch is connected to test equipment at the central office, wherein the first optical switch is capable of selectively connecting the test equipment to each of the optical fibers. A second optical switch is connected to the optical fibers in the subsequent optical cable on the opposite side of the splice. Portable test equipment is optionally connected to the second optical switch at the remote location. A portable controller is also taken to the remote location. The portable controller is used to control the first optical switch at the central office, via a telecommunications link. As a result, a person splicing an optical cable at the remote location can remotely instruct that cable to be tested in an automated manner from the central office. If the test shows a poor integrity in the splice, the cable can be cut and re-spliced until a quality splice is obtained.
U.S. Pat. No. 5,694,511 (Pimpinella, et al.) discloses an optical switching apparatus and method for use in the construction mode testing of a modular fiber administration system. The device and method for connecting an optical switch to the optical fibers that terminate on a fiber distribution shelf within a fiber administration system includes the optical switch device, which contains a support plate that is shaped essentially the same as the protective cover of the fiber distribution shelf. The support plate of the optical switch device can be joined to a specific fiber distribution shelf by substituting the support plate for the protective cover. An optical switch is affixed to the support plate, wherein the optical switch is sized not to extend beyond the peripheral boundaries of the support plate. As a result, when the support plate is placed over the fiber distribution shelf, the optical switch joined to the support plate does not obscure any other fiber distribution shelf in the fiber administration system.
U.S. Pat. No. 6,437,894 (Gilbert, et al.) discloses a fiber distribution shelf assembly for a fiber administration system having integral line tracing capabilities. The fiber administration system includes at least one fiber distribution shelve that supports a plurality of optical connection ports, each of which contains a sensor for detecting the presence of an optical coupling in that optical connection port. A systems controller is coupled to the sensor of each of the optical connection ports, the systems controller being capable of automatically determining from the sensors whether or not an optical coupling is present in each of the optical connection ports.
U.S. Pat. No. 5,530,546 (Barringer, et al.) discloses a method and apparatus for testing fiber optic jumpers, in which a station for testing fiber optic jumper cables includes four indexing plugboard stations. A single cable to be tested is typically attached to extend between two of the plugboard stations. Each plugboard station includes three columns of plug positions, corresponding to three styles of connecters, which may be used at the ends of the cable to be tested. An upper row and a central row of plug positions correspond to the contact types (PC or APC), which may be used. An indexing mechanism is provided to align one of the plug positions in the central row with a reference cable extending from the plugboard station. Reference jumpers extend from the upper row, being docked in a lower row of plug positions if the cable to be tested is connected to the central row, or being plugged into the central row if the cable to be tested is connected to the upper row. The reference cable extending from each of the plugboard stations is brought into and out of contact with one of the central-row plugboard positions, facilitating a sequence of tests. The reference cables from two of these plugboard stations are connected through an optical switch to an optical time domain reflectometer (OTDR), while the other two reference cables are simply connected to connectors at their far ends. A computer controls indexing the plugboard stations, and brings the reference cables into engagement according to a preferred sequence.
U.S. Pat. No. 3,884,585 (Lebduska) discloses fiber break detection methods for cables using multi-fiber optical bundles. A method and apparatus for detecting and assessing the light transmitting integrity of the individual fibers in a multi-fiber optic cable bundle is achieved by edge illuminating the bared fiber ends at an input terminal cable end, and detecting the quality of transmitted light emanating from the bared ends of the fibers at a receiving terminal cable end, The transmitted light emitting from the face of the receiving cable end is magnified by a microscope or the like. A second light source illuminates the surface of the receiving cable end to enable the faces of the broken fibers to be distinguishable from the remaining background. The end faces of the broken fibers will appear as dark, spots since the input illumination is absent, being interrupted by the break in the fiber somewhere along its length. The faces of the light transmitting unbroken fibers will appear as bright spots. A suitable camera attachment may be provided in conjunction with the microscope to obtain a permanent record of the magnified image of the output cable end.
U.S. Pat. No. 6,466,366 (Dominique) discloses a microscope with end plate and adapter for viewing multi-fiber connectors, in which a portable microscope includes an end plate and pivotable adapter for improved inspection of multiple fiber optic cables in a single connector. The end plate is mounted on the head unit housing of the microscope, and the adapter is mounted on a pivot cylinder extending from the end plate, the adapter including a jig for receiving and retaining a connector. Each fiber optic cable in the connector can be inspected one at a time by pivoting the adapter, so that each of the fiber optic cables is in view through the microscope. The adapter also includes an aperture, which is positioned over the head of the fastener used to connect the end plate to the housing. The pivoting movement of the adapter is limited by the engagement of the aperture against the head of the fastener. Various connectors are also discussed.
U.S. Pat. No. 5,731,893 (Dominique) discloses a portable microscope for inspecting fiber optic cable, in which a portable microscope includes an end plate with a reflective inner surface for improved inspection of the end surface of a fiber optic cable at a connection point in a fiber optic system. The end plate is mounted on the head unit housing of the microscope, and includes a tubular aperture for receiving and positioning the end of the fiber optic cable for microscopic inspection. A bowl is formed about the tubular aperture on the inner surface of the plate to direct more light to the end of the fiber optic cable. The outer surface of the plate includes a positioning tube for receiving a ferrule with the end of the fiber optic cable and directing the ferrule and fiber optic cable through the aperture into the bowl.
U.S. Pat. No. 6,412,987 (Horwitz, et al.) discloses an adapter system usable in conjunction with a fiber optic termination inspection microscope to inspect fiber optic cable end connectors. A plurality of different adapters for a fiber optic termination inspection microscope permits the microscope to be used with a plurality of cable connectors, where each cable connector has one or more cable termini. The purpose of the microscope is to inspect a cable terminus to determine if such is clean and polished, in order to insure low attenuation levels. If the cable terminus is dirty or scratched, the cable terminus can be replaced or repaired. An indicator can be used to disclose to the user exactly which cable terminus is being inspected.
U.S. Pat. No. 5,570,176 (Noel) discloses an apparatus for converting a multimeter to an optical power meter. An apparatus to convert optical power into a voltage includes a wavelength selector switch and can plug itself into a multi-meter. The converter apparatus comprises an annular connector, which adapts onto optical fiber connectors, which may be of various diameters. A photo-diode at the receiving end is large enough, so as not to require that the optical fiber be at a 90 degree angle to the photo-diode surface, so the surface gets a reasonable reading. A switch on the converter housing allows calibration of the converter at the appropriate wavelength to be used for the test. Optical power is then converted and sent as a voltage value through a pair of banana plugs that can be affixed to the multi-meter. A battery within the housing provides power to the converter, so that an external power source is not needed.
U.S. Pat. No. 6,439,776 (Harrison, et al.) discloses a fiber optic loop support, in which a testing device for fiber optic system devices includes a fiber optic loop support that holds a single-mode optical fiber, such that an empirically determined loss characteristic associated therewith is unvarying from use to use. In particular, an optical fiber forms a loop, and the loop is supported within a rigid slotted housing. The housing effectively precludes bending losses. Additionally, the housing is small and portable, so that field testing may also be performed. Various connectors are also discussed.
U.S. Pat. No. 6,388,741 (Beller) discloses a system for localization of faults in an optical fiber, in which an optical fiber is provided with a plurality of reflecting events spatially allocated along the optical fiber, for localizing possible faults in the optical fiber. Possible faults are localized by emitting a signal into the optical fiber, measuring the reflected signals, and comparing the measured reflected signals with expected signals representing the optical fiber without faults. If there are one or more faults in the optical fiber, the measured reflected signals at a distance behind each one of the one or more faults will show at least a different amplitude, or even disappear, with respect to the expected signals. The expected signals can be received or determined, e.g., from a previous measurement, such as an acceptance measurement, or can be calculated or otherwise received from theoretical analysis (e.g. simulation or modeling) and/or from information about the fiber, such as physical properties.
U.S. Pat. No. 6,363,198 (Braga, et al.) discloses an optical fiber cable distribution shelf with cable management system. The optical fiber cable distribution shelf comprises a cable management clip system in a rear bay, as well as a cable management clip system in the front bay of the shelf. The cable management clip systems each include at least one pair of controlled bend clips and at least one divider clip positioned therebeneath, in order to control bending of and to route optical fiber into and out of the cable distribution shelf, without imparting any undesirable fiber damage or related attenuated signals, owing to uncontrolled bending of the fibers. The optical fiber cable distribution shelf provides for installing a high density of fiber optic connections into an optical fiber cable distribution shelf.
U.S. Pat. No. 5,712,942 (Jennings, et al.) discloses an optical communications system having distributed intelligence, in which a distributed intelligence optical fiber communications system is capable of automated and continuous monitoring and testing of the optical fibers and their connections within the optical fiber distribution frames therein. The optical communications system has an optical distribution frame, including interconnection modules having actively intelligent microcontrollers thereon. The distribution frame includes electrical and optical interconnection fabrics between the distributed intelligence located on the interconnection modules and a host located outside of the distribution frame. The distributed intelligence interconnection modules allow monitoring, testing and/or related activities of the optical communications system to be performed locally at the interconnection modules. When used in combination with the electrical and optical interconnection fabrics, the modules reduce optical fiber routing, and enable effective monitoring and testing operations to be performed, while maintaining compatibility with existing conventional cross-connect, switching and network architectures.
U.S. Pat. No. 5,940,559 (Noll) discloses a fiber-optic test probe and connector adapter for testing fiber-optic connector harnesses and fiber-optic terminations, for example, in fiber optic connector assemblies. A single multi-channel connector adapter is provided that is adapted to be attached to the fiber-optic connector to be tested. In one embodiment of the invention, the connector adapter includes an alignment sleeve that enables the terminus of the fiber-optic connector to be tested to be axially aligned with the terminus of the test probe. In order to eliminate air gaps between the respective termini, the fiber-optic test probe and connector adapter are configured to provide axial compression forces between the mating termini in a test position, in order to eliminate air gaps therebetween, and thus reduce transmission losses. The test probe may be provided with strain relief and anti-bending boot, which prevents radial forces from misaligning the termini. The test probe includes a release sleeve that allows the test probe to be quickly released from its locked position. In an alternate embodiment of the invention, the alignment sleeve may be formed as part of the test probe. A probe calibration adapter, or feed-through adapter, is also provided, which enables two test probes to be coupled together for purposes of calibration. The feed-through adapter is configured to provide alignment between the respective termini of the test probe termini, while providing axial compression forces therebetween, similar to the adapter to reduce transmission losses, and thus improve performance while providing repeatability of the test measurements.
U.S. Pat. No. 4,940,892 (Fisher, et al.) discloses a optical discontinuity monitor system. A system for monitoring discontinuities in optical power transmitted through a fiber optic connector subjected to environmental stress is disclosed. Discontinuity events are defined in terms of amplitude and duration. The monitoring system comprises a detector unit, a fiber optic interface unit, and a discontinuity monitor. The detector unit converts the optical signal supplied by the fiber optic connector to electronic form. The fiber optic interface unit determines the amplitude of discontinuities, and the discontinuity monitor determines the duration of discontinuities.
Various fiber optic infrastructures, connectorized fiber optic drops, connectorized terminations, connectors, and fiber optic cables have been disclosed.
U.S. Pat. No. 6,721,482 (Glynn) discloses a telecommunications fiber optic infrastructure.
U.S. Pat. Nos. 6,539,147 and 6,522,804 (Mahony) disclose connectorized inside and outside fiber optic drops, in which connectorized fiber optic drops facilitates the deployment of fiber to the home by connecting a fiber optic interface device to an optical network terminal, the fiber optic drop including a sheath, transition fittings, pigtails, fiber optic connectors, and a fiber optic strand. The sheath is positioned over a middle section of the fiber optic strand. The transition fittings are attached to the fiber optic sheath proximate to both ends of the drop. The pigtails attach to the transition fittings and enclose the fiber optic strand from the transition fittings to the ends of the fiber optic strand, where the fiber optic connectors are attached to the fiber optic strand and the pigtails. If the drop contains more than one fiber optic strand, then one set of pigtails with connectors is provided for each fiber optic strand. Connectorized terminations are also discussed.
U.S. Pat. No. 6,496,641 (Mahony) discloses a fiber optic interface device that facilitates the deployment of fiber to the home by connecting a connectorized outside fiber optic drop to a connectorized inside fiber optic drop, the fiber optic interface device including a housing having two ports, termination hardware, routing hardware, and one or more adapters. The housing provides environmental protection and is adapted to be mounted to a customer's house. The two ports receive the outside and inside drops. Positioned above the ports inside the housing, the termination hardware secures the drops to the housing. The routing hardware receives the drops from the ports, routes the drops to the one or more adapters, and stores any extra length in the drops, while maintaining a proper fiber strand bend radius. The one or more adapters connect the outside drop to the inside drop, providing an aligned and stable fiber optic connection that does not require splicing. Connectorized terminations are also discussed.
U.S. Pat. No. 4,834,486 (Walker) discloses a connector sleeve adapter for mounting fiber optic connector sleeves having differing external shapes to a panel having an array of like shaped panel holes. A connector sleeve holder has multiple sidewalls having different shapes, in order to hold differing connector sleeves to a panel.
U.S. Pat. No. 3,663,822 (Uchida) discloses a multi-terminal optical cable, which includes an optical focusing fiber having a refractive index distribution in which the index varies in substantially inverse proportion to the square of the radial distance from the central longitudinal axis of the fiber to its outer periphery. A plurality of input electrical signals is converted into corresponding light signals at one end of the fiber. Those light signals are imaged by the fiber in a one-to-one relationship on an array of light sensing elements at the other end of the fiber at which the light images are reconverted to electrical signals, corresponding to the input electrical signals.
For the foregoing reasons, there is a need for a fiber optic tester that may be used by a field technician for testing a variety and plurality or multiplicity of connectorized fiber optic cables and/or devices simultaneously. The fiber optic tester should be quick, versatile, easy and simple to use, easily and quickly adaptable for use with different systems and configurations, inexpensive, long lasting, light weight, safe to use, attractive, sturdy, and durable, and capable of being used in the field for testing the fiber optic cables in a variety of installations and different circumstances. The fiber optic tester should be capable of being used as a continuity tester and determining whether or not there are breaks in the fiber optic cables being tested. The fiber optic tester should be a portable handheld fiber optic tester capable of being used in the field